The invention is related to apparatus for making ice cream and aerated soft drinks. It, more particularly, belongs to such types of apparatus that is suitable for home production of so-called soft ice cream and aerated soft drinks.
The use of injection of atmospheric air or carbon dioxide gas into a semifrozen mixture of ice cream base material by simultaneous stirring and freezing the mixture while admixing the gas has long been known as a method of producing an ice cream that is very softly textured and very palatable and attractive, and usually termed "soft ice cream".
A similar method of injecting gas, in particular carbon dioxide gas, into soft drink mixtures has been found to produce a soft drink that is very palatable and more attactive to most people than non-carbonized soft drinks.
Inventors have in the past devised various appararus for producing such aerated soft ice cream and soft drinks.
U.S. Pat. No. 1,408,774 by J.G.Peck, issued Mar. 7, 1922 describes a method of freezing ice cream by simultaneously freezing the ice cream mixture, beating it and injecting air or gas thereinto.
U.S. Pat. No. 1,978,176 by C. Steenstrup, issued Oct. 23, 1934 describes a method of making ice cream in an attachment to a household refrigerator.
U.S. Pat. No. 3,330,127 by A. H. Wakeman et al issued July 11, 1967 describes an aerating and refrigerating ice cream making apparatus with pressure responsive valve controlling the air supply.
U.S. Pat. No. 3,365,903 by H. G. Lutz et al issued Jan. 30, 1968 describes apparatus for preparation of soft ice or milk ice with air or gas injection to the ice cream mixture while it is being beaten or stirred.
U.S. Pat. No. 3,479,835 by C. Lane et al issued Nov. 25, 1969 describes a machine for producing and dispensing a semisolid, chilled, edible product that may be ice cream or a similar product based on other ingredients, and injects pressured carbon dioxide gas into the mixture.
U.S. Pat. No. 3,660,988 by G.Garavelli, issued May 9, 1972 discloses an ice cream making machine with a special container for combining and conveying the ice cream mix while a specific ratio of gas is added thereto.
The present invention discloses a novel apparatus for production of soft ice cream or soft drinks by means of gas injection that is uniquely constructed so that no rotating machinery or motors with shafts and paddles is required, but so that the injection of the gas under pressure through a suitably configured diffusion plate causes the mixture of ingredients to be agitated and kneaded by the force of the gas streams issuing from small apertures in the diffusion plate. Due to its mechanically simple and uncomplicated construction and its potentially small size, the ice cream maker according to the invention is especially well suited for home production of ice cream.
The invention permits the texture of the ice cream to be varied by means of a manual adjustment as described below in more detail in this specification.